thermal/drivers/mediatek/lvts: Add platform ops to support alternative conversion...

thermal/drivers/mediatek/lvts: Add platform ops to support alternative conversion logic

Introduce lvts_platform_ops struct to support SoC-specific versions of
lvts_raw_to_temp() and lvts_temp_to_raw() conversion functions.

This is in preparation for supporting SoCs like MT8196/MT6991, which
require a different lvts_temp_to_raw() implementation.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Laura Nao <laura.nao@collabora.com>
Link: https://patch.msgid.link/20251125-mt8196-lvts-v4-v5-3-6db7eb903fb7@collabora.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>